1. Field of the Invention
The present invention relates to an image forming apparatus and particularly to an image forming apparatus capable of displaying a capacity for storing sheets of paper to be printed and/or a remaining quantity of such sheets.
2. Description of the Prior Art
These days, apparatus for forming an image on paper based on prescribed information, such as copying machines, printers, and facsimiles are available.
In such an image forming apparatus, sheets of paper such as copying paper are stored in prescribed different containers (paper storing means) according to the sizes for example and a user selects a suitable size of paper or a suitable container as required so that an image may be formed on the paper.
At that time of forming an image by the above stated apparatus, the user sometimes wants to have information as to a remaining quantity of sheets in a specified container, a sheet storing capacity of that container or a quantity of sheets to be replenished in the container.
For example, at the time of copying a large number of sheets of paper, if the remaining quantity of sheets is known, it serves to determined whether sheets of paper should be replenished before the copy operation. In addition, based on the sheet storage capacity and the remaining quantity of sheets, the number of sheets to be replenished can be determined. Further, if a plurality of containers for storing sheets of paper of the same size are placed, information as to the number of sheets to be copied, the remaining quantity of sheets and the sheet storing capacity serves to determine what container is to be selected.
Such information is conveniently obtained, for example, when the user watches the sheets in the container. However, it is difficult to precisely ascertain visually the remaining quantity of sheets and the capacity of the container. In addition, if the container is placed in a position which can not easily be in sight, it is troublesome to obtain such information.
Under the circumstances, copying machines each comprising a single storing means for storing sheets of paper, means for detecting a remaining quantity of sheets in the storing means and display means for displaying the remaining quantity of sheets in response to the detecting means have been proposed recently and the U.S. Pat. Nos. 4,535,463 and 4,273,323 disclose such copying machines. However, neither of the United States patents teaches a technical thought that an image forming apparatus comprising sheet storage means is capable of displaying a capacity of the storage means.